The mass e-mail, which officials said went out shortly after 1 a.m., said MIT was taking an “important step relating to the Aaron Swartz situation,” accord­ing to a copy of the message posted by The Tech, the student newspaper.

The message, purportedly from MIT president L. Rafael Reif, also said in a passage that was not entirely clear that the university had “recieved [sic] several threatening requests from sources in the media.”

“Based on my initial reports, I believe it is best that we cancel classes for tomorrow,” it said.

MIT officials said that after they learned of the hoax, at 4 a.m., a university official ­e-mailed all students to notify them that the e-mail was fake and to tell them that classes would be held as scheduled.

MIT did not identify the hoaxer, but student ­Delian Asparouhov
took ­responsibility, calling
it “inappropriate.”

“This e-mail produced fear and caused many people to be angry that someone would take such a serious matter so lightly,” said
a statement attrib­uted to Asparouhov. “I’d like to apologize for the damage I caused to the MIT community, especially in light of the recent events that have caused large amounts of strife, which I only added to.”

The statement said the prank started as a late-night technical challenge among friends in which the writer was trying to show that it was easy to send prank e-mails under other people’s names. He said that when he sent the e-mails his “only thoughts” were that it would be “really funny” but that he quickly had misgivings.

“What started out as a way to prove a point, turned into a very, very stupid e-mail.”

If the Massachusetts Institute of Technology takes action against the student, all discipline would be internal and confidential, MIT spokes­woman Kimberly Allen said.

The hoax came just hours ­after Swartz’s father, Robert, called on the university to ­release all documents related to the case against his son, who committed suicide in January. Aaron Swartz was facing felony charges that he had hacked into an archive of academic journals on the university network.

In recent weeks, the university’s systems have been hacked at least three times. Last month, a hoax caller falsely ­reported there was a gunman on campus, saying he was retaliating for Swartz’s death.